Underfeed stoker



Nov. 4, 1930. R, s R-.LEY ET AL l y1,780,796

'UNDERFEED 510111111 Filed sept. 1s 1920 y 2 sheets-shed 1 S' i l WIW HEI-111111111111' -H l-Ilw-lnlfw 4 @l www;

Nov. 4, 1930. R, R|LEY ET AL i,'780,7 96 i '2l sheets-sheet 2 UNDERFEED STOKER Filed Sept.

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Parenteel Nov. 4, 1930 UNITED STATES ROBERT SANFORD R'TLEY AND JAMES 1T. MCELROY. Vor WORCESTER',A MASsAeTTiUsrrrrs",V

AssreNoRs To RILEY sToKER CORPORATION, .or WORCESTER, MASsACHUsnTTs,y A .LA

CORPORATION or .MAssACHUsETTs .l

NDERFEED sToKER Appiicaum'iV med september v1s,v 1er/zo.r lsaualin.1.1113151. .C f

This invention relates to an underfeed stoker ofthe usual type infvvhich coal'is fed into the front orouter endof one or more separate retorts. Such stolers are more com- I 45 monly. used for burning soft or bituminous coal and are ythen operated on the underfeed svstem,` thegcoal being gradually forced up- Ward fromv the bottom of the retort and the fuel'bed being replenishedV from below in- 10 stead of above.

' It is sometimes'found` necessary or desirable toI utilize such under-feed stokers for burning harder grades of fuelsuch as anthracitecoal. i Under these conditions it may be 1,5 found desirable 'to change the operation of the Stoker from the'distillation system of com bustion to the overfeed system of combustion. It is the general object of our invention to provide a Constructionvby which 'an'underf feedstoker may be thus changed forv over`- feed combustion, Witha minimum expediture'oftime or labor. r l

With this general object in vievv anim-y portant feature of our invention consistsv in adapted to be secured Within anun'derfeed retortof the usual type. l f

Other features ofour invention relate to the provision of means for controlling the supply of air to such an overfeed grate, and to means for reciprocating the grate longitudinally when found desirable.

' Our'invention further relates to arrangements and combinations-of parts which will be hereinafter described and morev particularly pointed out in theappended claims.

A preferred form of our invention is shown in the drawings in Which I Figl is' a longitudinalverticalnsectional elevationof a stoker With parts Vat Vthe 4front 'and rear shown diagrammatically having our improvements embodied therein; V

1 Fig. 2fis an enlarged sectional elevation of the-auxiliary grateshowing also certain parts ofthe Stoker adjacent thereto;

A Fig. 3y is a transverse'sectional elevation taken along the line 3 3 in Fig 2;

1 *.Fg. 411s a detailsectional View to bedescribedg andI f .Y i f the provision of a removable overfeed grate Fig. 5- is a sectional actuating mechamsm.-

Referring to the drawmgs We have sh'ovsn a section of an underfeed stoker of a common type, having a front Wall' 10,` a rear Wall 11, a feed hopper 12, a ram 13^for forcing the coal from the hopper tothe retort, av crankplan -vieW of. `certain shaft 141f0r reciprocatingthe?ram-'13,l and driving mechanism 115 connectedthrough a gear box-16 to drive the crank'shaftl14. At

ythe' rear of the retort a rock-ing discharge plate 17. assists the rearward movement vof the ash and' Waste to thel discharge opening 18. Thechamloer 19 beneath the retorts is enclosed 'at the' sides andl isf adaptedltovvcontain airunder pressure f Each retort'preferably comprises a bottom plate 20 (Fig. 3) and side Walls 21 provided With air admitting openingsQQand common-A ly movable longitudinally by drivingconneoi tionsiof the usual commercial'ty'pe such' asare shoW'nfor instanceinL the applicant-Rileys prior Patent No. 1,090,651-,issuedM'arch* 17 1914. j l

Such driving connections are indicated in 5, Which'shovvs the coal-feeding ram 18 provided With a cros'sbar 40 havin'gopenings in its opposite vends through which threaded rods'41 are freely slidable. These rods 41 are secured in 'slid'ably moun'ted'members 42.2Which in turn are directly secured to the movable side Walls 21.

VThe lrods 41 are provided v'vithkheadsv 43 adapted to be engaged by "one side of the cross-bar 40, and with nuts 44 adapted'tobe engaged by the opposite side of the'cros'sbar as the ram is reciprocated.

The side Walls 21 thus have a lost moti'o'n connection With'the coal-feedingramand partake ofthe motion lof the ram duringanyd'esired portion ofisu'ch motion; Theextent of motion of Vthe sidewalls may be adjustedbyturningy the'rodsi41 inthe slidable members 30? v as Vshown in Fig. 4. x

i Q Any suitable mechanism may be VprovidedV V2l5`for reeiprocating .the member 23. In theV y'appearance --v'shown in 2 and The l' front end' of the grate member is formed as a closed plate Maand the opposite end of the member isY constructed to lact as 'an overfee'd grate surface, and lfor this V.purposeyis proi yx'fidedwithfairy openings 25. Thev gratemem- ,ber is also provided with.l sidewalls 26 con- U nected by` cross bars 27 'through which eX atend bolts -28 by'whic'h the grate member is se' cured tothebottom-plate Q0. Air openings 29 are formedin the bottom plate 2O so that Y air'may pass fromthe air cham'bergl)k to the openings in the grate member. 'When the grate ymember 23is removed and the-Stoker is 15vv operated as anunderfeed stoker, the air openings 29maygbe elo-sed by suitable cover plates It is sometimes kdesirable to reciprocate the grate member ;23,and' with this in viewitlie bolts 28 extend through slots inthe bottom plate20. When the member 23 is to be reciprocated' the ,bolts 28 may be loosened Ysufliciently to permit such relative movement.'Y

drawings we have shownza rod 30 boltedyto Y the endQLl of the member and having its (outer 'ends extending-through.anopening in VVthe ram 13. Nuts 31 adjustable-:on the rod Ysor Solare. engaged by the rain 13 as it moves backwardjand forward, and. a reduced in terf VInittent motion is thusconveyedto the mem- Having thusfdescribedV our Vinvention,-the 35 operation and advantages thereof'will be readilyy apparent. For distillation combustion vthegstoker vis operated as-usual, theair openings 29 beingsuitably closed. YFor over-y feed combustion the grate member 23 is placed inthe retort and is secured to thebottom plateV "b OltS 28. -If itV is -found desirable toA re# f ciprocatethe member 23,` the bolts 28V are Y 1 H2.' Inl an underfeed Stoker, an un'derfeed re#V itort, l"al grate member movable longitudinally loosened and the nutsl arejsui'tably ad! justedV on the rod 30;l Thestoker maybe 'thus readily adapted to thefuel available'.

l Having vthus described our invention it willbeevident thatichanges andmodifica-V l t-ion canfbemade-therein byfthosey skilled in the art v'vithin. thes'piritV andjfscope joffour inventionv'asfset forth inf the claims, and we donot wishpto beA otherwise limitedto the detailsherein disclosed,; but what we claim r1s:. n.

Yla'.v yIn an underfeed Stoker, an underfeed retort, -a grate-member movable vlon-gitudinally .Y insaid retort andef'feetivev to elevate the fuel 'forward' movementv thereof,and means tov reciprocate saidfgrate member 'in said retort,

vs aid-gratefmember having provision forcen-k rducting. air therethrough to fuel 1n :said re-l in saidretortl and efectiveto elevate the fuel.y by forward Iliiovement j thereof "and Ito feedv the fuel rearward by rearward movement thereof, and means to'reciprocate saidl grate member in said retort, said grate member having provision for conducting air there'- through to fuel in said retort.-V y

f In' anv underfeed stoker,1in combination,`

an underfeed retort, amovable grate'member effective tosupply air for combustion offuel tion of said grate member. Y p p n 4.' In'an underfeed stolzer, in combination,

anunderfeed retort, a movable grate member disposed entirely within said retort and effec-f tive to supply air forcombustion of'fuel in said. retort, means vto admit air beneath said' grate member, and meansto move said grate member longitudinally in saidwretor't;

5. In anunderfeed-jstoker,-in combination, anunderfeed retort .having a bottom plate,ra movable grate member locatedentirely withe kin saidv retort, and means'to move Isaidfgr'ate member, the fuel capacity; of 'said retortre-'Y' maining the 'samey for every operative'posi- Y in said retort above said bottomv plate and." i

effective'tofsupplyfair for combusti-on of fuel vin' said retort, means to: slidablysecu-re -said grate member on. said ybottom plate within'.

support said grate member in said retort, a

fuel feedingrain 'for saidretort,V driving mech.anism -therefor,and a lost motion con'- nection between said Vram .andfsaid grate member.. m u

' .7.- `In an underfeedstoker, in combination, an underfeed-retort having `side walls .proivid'ed withtuyere openings, ajram to `move' the fuel rearwardV inthe' retort anda lgrate memberin said retort effective to supply air to the fuel in. said retort throughoutv a, major portionof the lengthvof said retort, said grate member i-being of substantially the :width of the retort andhaving anup'wardly andl rearwardly inclined front surface effective vto ele'- vate the fuel in the retort as said fuelfismoved rearward ^relative .to-'saidgratememben' f Y 8. furnace having,` in combination, a downwardly and; rearwardly inclined'fuel retort having side walls -longitudinallymovable,tuyre structuresmounted,on said side walls, means for reciprocating saidsidefwalls longitudinallyand forjfeeding the'ffuelfinto the'forward ofthe retort, vand, atuyre structure mountedv on' vthe l inclined bottom Wall ofthe retortY of i substantiallyltlie Awidth f i of and extending substantially they length ,of

the retort for 'supplying-*Fair Vto-'the fuel* Y throughout..substantially'thearea of they tort. i

An underfeed{Stoker-,Y having "tuyeres 'Y mounted upon the side walls of the underfeed retorts through which the main supply of air is admitted to the fuel bed, supplementary air admission means located within each retort between the side walls thereof for admitting a supply of air int-o the portions of the fuel bed situated over the centers of the retorts and at Various points along the length thereof, means for moving said supplementary air admission means, and means for moving the side walls so as to assist in slicing and advancing the fuel bed.

y l0. An underfeed Stoker comprising movable side walls, air admission means carried by said moving side walls, supplementary air admission means `located within each under-v feed retort between the movable side walls therof, for agitating and breaking up the fuel as it is advanced down the retort, means for moving said supplementary air admission means so that said supplementary air admission means serve both to admit a supply of air into the portions of the fuel bed positioned over the center of each retort so as to aerate the fuel and simultaneously to cool and prevent burning out of the airadmission and agitating means.

11. In an underfeed Stoker, an underfeed retort having side Walls, tuyre structures mounted on said side walls, a ram to move the fuel rearwardly in the retort, and a grate member between the retort walls which is of substantially the width of the retort and eX- tends substantially the length thereof, said grate member having tuyre openings. effective to supply air to the fuel in said retort throughout substantially the entire area of the retort.

12. In an underfeed stolzer, an underfeed retort having side walls provided with tuyre openings, a ram to move the fuel rearwardly in the retort, and a fuel supporting grate member between the retort walls which is of substantially the width of the retort and extends throughout the major portion of the length thereof, said grate member having a downwardly and rearwardlv sloping face eX- tending the major portion of its length and having rearwardly directed tuyre openings throughout its entire rearwardly sloping face effective to supply air to the fuel in said retort.

In testimony whereof we have hereunto aiiXed our signatures.

ROBERT SANFORD RILEY. JAMES H. MGELROY. 

